Wheeled cart for material management system

This invention relates generally to material management systems and relates, more particularly, to a transportable material cart upon which items are placed for use at a job site or for storage. Once items are placed thereon, the material cart can be bodily transported by way of, for example, a forklift truck, in order to move the items from one site to another. An example of a material cart having inventors in common with those of the instant invention is shown in U.S. Pat. No. D781,080.

Some material carts of the class to which this invention relates possess wheels, or casters, which enable the cart to be wheeled between two sites while the wheels move in rolling engagement with an underlying floor or support surface.

It would be desirable to provide a wheeled material cart of the aforedescribed class whose wheels can be shifted in position from a condition of use at which the wheels engage the floor or underlying support surface to enable the cart to be wheeled across the floor or underlying support surface and an out-of-the-way condition at which the wheels are prevented from interfering with the placement of the remainder of the cart flatly upon the underlying floor or support surface. One such support surface may be the bed of a truck with which the material cart can transported, or driven, from one site to another by way of the truck.

Accordingly, an object of the present invention is to provide a new and improved wheeled material cart whose wheels can be shifted in position from a condition of use which enables the cart to be wheeled, or rolled, across a floor or underlying support surface and an out-of-the-way condition at which the wheels are prevented from interfering with the placement of the remainder of the cart flatly upon the underlying floor or support surface.

Another object of the present invention is to provide such a new and improved material cart which can be positioned in a stacked relationship with material carts of like construction.

Still another object of the present invention is to provide such a material cart which is uncomplicated in construction yet effective in operation.

This invention resides in a material cart capable of supporting or storing items for use at a jobsite.

The material cart includes a base frame which defines a bottom surface which lies substantially in a horizontal plane. Also included in the cart are a plurality of wheel-including casters which are attached to the base frame. In addition, the casters are attached to the base frame in a manner which permits a pivotal movement of the wheels of the casters relative to the base frame between a condition of use at which the wheels of the casters engage the floor or underlying support surface and thereby permit the base frame to be wheeled to an alternative site and an out-of-the-way condition at which no portion of the wheels of the casters is disposed beneath the horizontal plane in which the bottom surface of the base frame lies so that the bottom surface of the base frame can be lowered onto the floor or underlying support surface without interference from the wheels of the casters.

Turning now to the drawings in greater detail and considering first, there is illustrated an embodiment of a wheeled material cart, generally indicated, within which features of the present invention are embodied. Briefly, the material cartincludes a base frameupon which a plurality of rack components, generally indicated, are positioned for supporting construction materials, such as conduits, supported by the rack componentsfor use at a job site. Meanwhile, the cartalso includes a plurality of (i.e. six) wheel-including casterswhich are joined to the framefor movement relative to the cartbetween a condition of use at which the wheels of the castersengage the floor(or other underlying support surface) and thereby support the weight of the cart(and any materials supported thereby) as the cartis wheeled across the floorand a condition of non-use at which the wheels of the castersare disposed in an out-of-the-way condition (at which the wheels of the castersare out of engagement with the floor) so that the framecan be lowered to the floorwithout interference from the casters.

With reference still to, the base frameof the depicted material cartis substantially rectangular in shape and is constructed of steel channel membersandwhich are joined (i.e bolted or welded) together at the corners of the frame. More particularly, a pair of channel membersare arranged in a spaced and parallel relationship with one another to provide two opposite sides,of the cart, and a pair of channel membersare arranged in a spaced and parallel relationship with one another to provide two opposite forward and trailing ends,, respectively, of the cart. In addition, there is associated with each of the channel members,and cross memberan end portion′,′ or′ which protrudes from a corresponding one of the opposite sidesandof the cartand which is disposed outboard of the sides,of the frame. As will be apparent herein, it is through these protruding end portions′,′ and′ that the wheeled castersare joined to the frame.

Each of the channel members,which provide the opposite sidesorof the framedefine a pair of spaced-apart through-openingswhich open out of the sides,of the frameand which provide openings for the forks of a forklift truck (not shown). For a reason which will be apparent herein, the framedefines a bottomwhich, as is depicted in, lies in a substantially horizontal plane, indicatedin the side elevation views of. As will be apparent herein, when each casteris positioned in its out-of-the-way condition, the frameis free to be placed flatly upon the floor() or underlying support surface unobstructed by the wheels of the casters.

With reference toand as exemplified by the casterdepicted in these Figures, each casterincludes a support platewhich is substantially square in shape (as seen from above in) and also includes a bifurcated portionhaving two forkswhich are joined (e.g. welded) to the underside of the support plateso that the lower ends thereof extend downwardly from the plate. Moreover, the support platedefines a (vertically-opening) through-openingadjacent each of the four corners thereof for a reason which will be apparent herein. A set of aligned through-openingsare defined in the forksand open along horizontal axes, and a wheelhaving a central openingis positioned between the forksso that the central openingis aligned with the through-openingsdefined in the forks. In addition, the shank, indicatedof a pin, or bolt, is directed through the aligned through-openingand central openingto journal the wheelto the bifurcated portion. A key (e.g. a Cotter key)is secured to the end of the bolt shankopposite the head end thereof to prevent the inadvertent withdrawal of the boltfrom the aligned through-openingsand central opening.

In addition, each caster wheelis pivotally secured to a corresponding protruding portion′,′ or′ () of the cart frame. To this end and as best shown in, there is associated with each castera support assemblywhich is provided with a pair of spaced-apart legsand a square-shaped bearing platewhich extends between and is secured to the legs. The bearing platedefines an openingadjacent each corner of the plate, and the shank of a boltis directed through both the openingand the preformed opening(introduced earlier) of the support platewhich is aligned with (a corresponding) openingdefined in the bearing plate. A nutis securable about the shank of each boltto thereby secure the support plateof the bifurcated portionof the casterto the support assembly.

Each support assemblyis, in turn, pivotally joined to a corresponding one of the protruding portions′,′ or′ () to thereby secure the castersto the frame. To this end, each protruding portion′,′ or′ is provided with a series of through-openings,or(best shown in) wherein each through-opening,oropens along a horizontal axis. As best shown in, the series of through-openings,orare grouped in somewhat of a substantially vertical arrangement. Meanwhile, the legsof the support assemblydefine a set of three through-openings,orwherein each through-opening,oropens along a substantially horizontal axis and are grouped in somewhat of a triangular arrangement.

For purposes of securing the support assemblyto a corresponding one of the protruding portions′,′ or′, the support assemblyis first arranged about it corresponding protruding portion′,′ or′ so that the legsof the support assemblyare positioned on opposite sides of the protruding portion′,′ or′ (as best shown in) and so that the through-openingswhich are defined in the legsare aligned with the through-openingwhich is defined in the protruding portion′,′ or′. Next, the shankof a bolt() is directed through the aligned through-openings,, and a keyis secured to the end of the bolt shankopposite the head end thereof to prevent the inadvertent withdrawal of the boltfrom the aligned through-openings,. With the casterthus arranged in its position depicted inat which the protruding portion′,′ or′ rests upon the bearing plateof the support assemblyof the caster, the through-openingsdefined in the legsof the support assemblyare aligned with the through-openingdefined in the protruding portion′,′ or′, and the shankof a boltis directed through the aligned through-openings,, and a keyis secured to the end of the bolt shankopposite the head end thereof to prevent the inadvertent withdrawal of the boltfrom the aligned openings,. With each casterjoined to a corresponding protruding portion′,′ or′ as shown inso that the wheelof the casterengages the floor(or underlying support surface) and both bolts,are positioned through the corresponding set of aligned openings,and,, the casteris in its position of use so that collectively, the castersenable the cartto be wheeled, or rolled, across the floorto an alternative site.

It is a feature of the aforedescribed attachment between each casterand its corresponding protruding portion′,′ or′ enables the casterto be pivoted relative to the framefrom thecondition of use (and in the direction of thearrow) to an out-of-the-way position (as depicted in) at which the caster wheelno longer engages the floorand is, instead, disposed to one side of the frame. In order to pivot the castersin such a manner, the keyis first removed from its secured condition within the bolt shankof the bolt, and the boltis then removed from the aligned through-openings,so that each casteris free to be pivoted in the direction of thearrowabout the bolt shankand relative to the protruding portion′,′ or′ to which the casteris pivotally secured. Once each casteris pivoted to the out-of-the-way position, as is depicted in, the through-openings,() defined in the support assemblyand the corresponding protruding portion′,′ or′ are aligned with one another. At that point, the (previously-removed) boltis directed shank-end-first through the aligned through-openings,of the support assemblyand the protruding portion′,′ or′ to secure the casterin theout-of-the-way condition.

One advantage provided by the material cart(and the manner in which the castersare attached to the cart framerelates to the fact that upon movement of and securement of all of the castersin theout-of-the way condition, the base frameof the cartis free to be lowered onto the underlying flooror other support surface, such as the bed of a truck (not shown) for transport of the cartto an alternative site. In other words, once the castersare each moved to and secured in place in theout-of-the-way condition, the castersprovide no impediment or interference to the lowering of the base frame(and any load supported thereby) onto the underlying floor. It will be understood that if any load is supported upon the base framewhen it is desired that the castersbe pivotally moved from thecondition of use to theout-of-the-way condition, the cart framecan be lifted with a forklift truck (not shown) by way of the forklift openings() provided in the sides,of the frame. It also follows that a forklift truck can also be used to lower the cart frameto an elevated condition in order for an operator to return the castersfrom the out-of-the-way condition to thecondition of use. In order to return each casterfrom theout-of-the-way condition to thecondition of use (and re-secure the castersin thecondition of use, the aforedescribed steps followed to move each casterfrom thecondition of use to (and to secure each casterin) theout-of-the-way condition are reversed.

The aforedescribed capacity to lower the cart frameonto an underlying support surface can be particularly advantageous if the underlying support surface is the bed of a truck for cart-transporting purposes. More specifically and if the caster wheelsof the cartwere to remain in thecondition of use when positioned onto the bed of a transport truck so that the caster wheelswere required to bear the weight of the material cart (and any load positioned thereon), the caster wheelscould be damaged by any shaking or jostling of the truck bed during transport. But by removing the wheel-including castersfrom beneath the base frameof the cart(and securing each casterin itsout-of-the-way condition) prior to a loading of the cartonto the truck bed (so that the frameof the cartcan rest directly upon the truck bed), any likelihood of damage to the wheelsof the castersduring transport (e.g. by way of any shaking or jostling of the truck bed) is circumvented.

Once again, it will be understood that unless the wheelsof the castersare positioned in thecondition of use, the cart(and any contents borne thereby) must likely be lifted by way of a forklift truck (not shown), but the provision of the forklift openings() provided in each sideorof the material cartaccommodate the use of a forklift truck for this purpose.

Another advantage provided by the depicted cartrelates to the provision of the bearing plateprovided with each caster. In this connection and as best shown in(at which the casteris positioned in its condition of use), the base framerests directly upon the bearing plate, and it is through this bearing platethat the weight of the casteris transferred to the underlying wheelof the caster. This means that it is the bearing platewhich bears the weight of the cart frame(and any load supported thereby) rather than through the boltwhich is used to pivotally secure the casterto the protruding portion′,′ or′ of the cart frame. Thus, the provision of the bearing plateswithin the castersreduces the likelihood of damage to the boltswhen the weight of the material cartmust be borne by the casters.

Still another advantage provided by the material cartrelates to its capacity to be arranged in a stacked relationship with a material cart of identical construction to that of the aforedescribed material cartof. For example and if the rack componentswere removed from thecart, the cart framewould be left with a (bare) upper surface which lies in a substantially horizontal plane. Meanwhile, the frame of an identical material cart—with all of its castersarranged in theout-of-the-way condition, could be lowered onto the upper surface of the cart framefor stacking purposes. Accordingly, the capacity of the material cartto be stacked with cart frames of like construction is advantageous in this respect.

It follows that a material carthas been described which includes a base framewhich defines a bottom surfacewhich lies substantially in a horizontal planeand also includes a plurality of wheel-including casterswhich are pivotally attached to the base framein a manner which permits a pivotal movement of the wheelsof the castersrelative to the base framebetween a condition of use at which the wheelsof the castersengage the flooror underlying support surface and thereby permit the base frameto be wheeled to an alternative site and an out-of-the-way condition at which no portion of the wheelsof the castersis disposed beneath the horizontal plane in which the bottom surfaceof the base framelies so that the bottom surfaceof the base framecan be lowered onto the flooror underlying support surface without interference from the casters. Moreover, the casterscan be secured in either of these two conditions.

It will be understood that numerous modifications and substitutions can be had to the aforedescribed embodimentwithout departing from the spirit of the invention. Accordingly, the aforedescribed embodimentis intended for the purpose of illustration and not as limitation.